log the "merged" root when validating roots

chain/src/types.rs

@@ -20,7 +20,7 @@ use std::sync::Arc;
 use crate::core::core::hash::{Hash, Hashed, ZERO_HASH};
 use crate::core::core::{Block, BlockHeader};
 use crate::core::pow::Difficulty;
-use crate::core::ser;
+use crate::core::ser::{self, PMMRIndexHashable};
 use crate::error::{Error, ErrorKind};
 use crate::util::RwLock;
 
@@ -217,18 +217,19 @@ pub struct TxHashSetRoots {
 impl TxHashSetRoots {
 	/// Accessor for the underlying output PMMR root
 	pub fn output_root(&self) -> Hash {
-		self.output_roots.pmmr_root
+		self.output_roots.output_root()
 	}
 
 	/// Validate roots against the provided block header.
 	pub fn validate(&self, header: &BlockHeader) -> Result<(), Error> {
 		debug!(
-			"validate roots: {} at {}, output_root: {}, output pmmr: {} (bitmap: {})",
+			"validate roots: {} at {}, output_root: {}, output pmmr: {} (bitmap: {}, merged: {})",
 			header.hash(),
 			header.height,
 			header.output_root,
-			self.output_roots.pmmr_root,
+			self.output_roots.output_root(),
 			self.output_roots.bitmap_root,
+			self.output_roots.merged_root(header),
 		);
 
 		if header.output_root != self.output_roots.pmmr_root {
@@ -252,6 +253,20 @@ pub struct OutputRoots {
 	pub bitmap_root: Hash,
 }
 
+impl OutputRoots {
+	/// The root of the underlying output PMMR.
+	pub fn output_root(&self) -> Hash {
+		self.pmmr_root
+	}
+
+	/// Hash the root of the output PMMR and the root of the bitmap accumulator
+	/// together with the size of the output PMMR (for consistency with existing PMMR impl).
+	/// H(pmmr_size | pmmr_root | bitmap_root)
+	pub fn merged_root(&self, header: &BlockHeader) -> Hash {
+		(self.pmmr_root, self.bitmap_root).hash_with_index(header.output_mmr_size)
+	}
+}
+
 /// A helper to hold the output pmmr position of the txhashset in order to keep them
 /// readable.
 #[derive(Debug)]